People with human immunodeficiency virus (HIV) are more prone to sudden cardiac death (SCD) than the general population, say researchers.

The team found that HIV-infected patients suffered SCD at a rate more than four times higher than that expected in the general population with similar risk factors.

“As part of my ongoing research in 2010, we were looking at every instance of sudden death in San Francisco,” said lead study author Zian Tseng, from the University of California-San Francisco in the US. “I noticed that many of these cases involved individuals with HIV infection who were dying suddenly. I wondered if there was some sort of connection.”

To address this, Tseng and co-investigators retrospectively examined the records of 2,860 consecutive HIV patients from April 2000 to August 2009. They studied medical records, death certificates, paramedic reports, and interviews with family members, doctors, and other clinicians.

The researchers report a total of 230 deaths over a median 3.7 year follow-up period. Of these, 13 % met SCD criteria.

Cardiac-related deaths accounted for 15 % of overall mortality and, of that group, 86 % died of sudden cardiac death.

“To put that in context, we’re able to compare the rate of sudden death in this population with the overall San Francisco population,” said Tseng. “So adjusted for age, race, demographics, and other variables, the rate of sudden death in the HIV population is more than four times higher than the general population.”

Study co-author Priscilla Hsue, from the HIV Cardiology Clinic at San Francisco General Hospital and Trauma Centre, added: “The fact that the vast majority of cardiac deaths were sudden is surprising and implies that we as clinicians need to be aware of this potential health issue among patients with HIV.”

She also said that these findings highlight many things that remain unknown about HIV and sudden death. “Did these individuals die of unrecognized coronary artery disease? What can we be doing as clinicians to identify patients at risk and to intervene beforehand?” she asked.

The researchers conclude, in the Journal of the American College of Cardiology, that “greater attention must be directed to the mechanisms underlying SCD, with the goal of identifying at-risk patients and ultimately preventing sudden death.”

By Nikki Withers